The present invention is directed to a process of forming an improved laminate of aramid paper and a polymer layer, preferably a laminate of two aramid papers separated by a polymer layer.
Japanese Patent Publication 8-99389 discloses formation of a laminate sheet of m-aramid paper and a polyester film employing calendering and rapid cooling of the formed laminate.
British Patent 1,486,372 discloses a metallic layer adhered to a nonwoven web of a blend of different staple fibers which have been compacted and held together with a matrix of film-forming high molecular polymeric binder material.
Hendren et al. U.S. Pat. No. 5,320,892 discloses a laminate for honeycomb structures formed from a core containing poly (m-phenylene isophthalamide) fibrids and outside layers of a floc and fibrids of poly (mphenylene isophthalamide).
Ootuka et al. U.S. Pat. No. 5,948,543 discloses formation of a laminate base material of aromatic polyamide fiber non-woven fabric formed from fibers of para-aramid and meta-aramid bonded with a resin binder.
Laminates made from aramid sheet(s) or paper(s) and polymer layer(s) are useful in transformers wherein the laminate serves as dielectric insulation material. Any improvement in the internal adhesion of the laminate or the tear or elongation at break properties of such laminates is desirable.